PSLE A shop is having a book sale.
The 1st book is at 15% discount.
The 2nd book is at 35% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Abi and Tommy each bought two books at the sale.
- Abi's books were priced at $13 and $22. How much more did she pay for the 1st book than the 2nd book?
- Tommy paid a total of $29.55 for his two books. He paid $6.15 less for the 2nd book than for the 1st book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $22 |
100% $13 |
|
Discount |
- 15% |
- 35% |
|
Sale price |
85% |
65% |
? |
(a)
Selling price of the 1st book
= 85% x 22
=
85100 x 22
= $18.70
Selling price of 2nd book
= 65% x 13
=
65100 x 13
= $8.45
Amount that Abi paid more for the 1st book than the 2nd book
= 18.70 - 8.45
= $10.25
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 15% |
- 35% |
|
Sale price |
85%
|
65%
|
|
Compare 1st book and 2nd book |
1 u + $6.15 |
1 u |
$29.55 |
(b)
Sale price of the 1st book = 1 u + 6.15
Sale price of the 2nd book = 1 u
Total amount that Tommy paid
= 1 u + 6.15 + 1 u
= 2 u + 6.15
2 u + 6.15 = 29.55
2 u = 29.55 - 6.15
2 u = 23.40
1 u = 23.40 ÷ 2 = 11.70
Sale price of the 1st book
= 1 u + 6.15
= $17.85
85% of the price = $17.85
100% of the price =
17.8585 x 100 = $21
Selling price of the 1st book before discount = $21
Answer(s): (a) $10.25; (b) $21